We are looking for WIMPs in the Soudan Underground Lab in Northern Minnesota using ultra-cold solid state detectors. The next step, SuperCDMS, will be installed in a mine in Canada that is even deeper. Data from our last run should be announced in late October. I'll explain our techniques and what it is like to play pingpong half a mile underground.

Laser Interferometer Gravitational-wave Observatory (LIGO) has built three multi-km interferometers designed to search for gravitational waves. LIGO has reached its design sensitivity, and the first year-long run is expected to end on October 1, 2007. The data from this run will be thoroughly searched in the coming years for different sources of gravitational radiation. At the same time, detector upgrades will be commissioned with the goal of improving interferometer sensitivity by a factor of 10 and of increasing the sensitive frequency band of the interferometers. We will review the current status of LIGO and the expected future improvements, as well as the most recent results of the search for stochastic gravitational-wave background.

Fluorescence Fluctuation Spectroscopy of Biological Systems: What optical noise can teach us about proteins, cells and viruses?

Every cellular process involves a complex network of protein interactions. The rules and design of these networks are currently poorly understood. It is our goal to directly visualize these interaction networks on the molecular level to contribute to the physical and biological understanding of living systems. We exploit optical signal fluctuations originating from single protein molecules to learn about the assembly, transport, and interaction of biomolecules. I’ll explain the technique and discuss applications ranging from gene regulation to the assembly of the HIV virus.

The space between the Sun and the planets in the solar system is not empty; instead, it is filled with a very tenuous, ionized gas known as plasma. This plasma is strongly influenced by the magnetic fields produced in the Sun and the various planets. The Space Plasma Physics group at the University of Minnesota studies these plasmas in a variety of ways. We have designed and built instruments measuring electric fields and waves on a variety of NASA spacecraft studying the solar wind, the Earth’s magnetosphere and radiation belts, and the processes that produce the aurora. Our research is focused on two main questions: (1) How do the electric and magnetic fields in space accelerate charged particles to high energies (e.g., up to MeV in the radiation belts)? (2) How do magnetic fields reorganize themselves when, for example, the magnetic field in the solar wind interacts with the magnetic field of Earth, a process known as magnetic reconnection? These questions are answered not only with direct spacecraft measurements but with theory and modeling to understand the complex plasma interactions that can take place in the solar system, as well as in other astrophysical systems.

We use the translation machinery of a cell-free expression system to reconstruct genetic circuits in vitro. Expression of elementary gene circuits can be carried out in batch mode or continuous mode to study quantitatively the properties of genetic circuits. The extract can be also encapsulated in synthetic phospholipids vesicles. This system is used as a model of protocell programmable with DNA. One of the challenges of this engineering approach is to reach homeostasis by (1) maintaining efficient in vitro expression on long period of time by feeding the vesicles, (2) degrading selectively the synthesized messengers and proteins. Perspectives and limitations of this approach will be discussed.